How will software development and operations have to change to meet the sustainability and green needs of the planet? And what does that imply for development organizations? In this eye-opening book, sustainable software advocates Anne Currie, Sarah Hsu, and Sara Bergman provide a unique overview of this topic - discussing everything from the likely evolution of national grids to the effect those changes will have on the day-to-day lives of developers. Ideal for everyone from new developers to CTOs, Building Green Software tackles the challenges involved and shows you how to build, host, and operate code in a way that's not only better for the planet but also cheaper and relatively low-risk for your business. The problem with code efficiency is that although cutting CPU GPU use can potentially have a huge impact on carbon emissions and is well understood - the same techniques have been used for many decades in high-performance computing (HPC) - it is high effort for engineers. You might get a hundredfold reduction in carbon emissions by switching, for example, from Python to a much more efficient language like Rust, but there will be a price to pay in productivity. Developers really do deliver much more quickly when they are using lower machine-efficiency languages like Python.